Variation of gene expression profile linked to p27 Kip1 Ser10 phosphorylation status in MCF-7 cell line

Ser10 was the major phosphorylation site in p27Kip1 (here after referred to as p27), accounting for 70% of the total phosphorylation of this protein, due to cytoplasmic shuttling. To further elucidate the mechanism for Ser10-mediated dysfunction of p27 during breast cancer progression. Affymetrix Human Genome U133A Array was used to identify differentially regulated genes between MCF-7 breast cancer cell lines stably-transfected with wild type and Ser10 mutant (substitution of Ser10 with Ala, S10A), alternatively. Then to confirm by RT-PCR then western blot partly. Microarray analysis showing that S10A, then abrogation of Ser10 phosphorylation, result in important changes in a large number of genes involved in the control of cell cycle, cell differentiation, metabolism, immune response and signal transduction. S10A induced cell cycle G0 phase arrest by FACS method. And cell growth inhibition and abrogation of cytoplasmic translation. Our data indicate that abrogation of phosphorylation of Ser10 resulted in significant changes in gene expression profiles which mediate cell cycle redistribution, sub-cellular localization.